A navigation system (global positioning system or GPS) performs travel guidance for enabling a user to easily and quickly reach the selected destination. A typical example is a vehicle navigation system where a vehicle is equipped with a navigation function to guide a driver to a destination through a calculated route. Such a navigation system detects the position of the user's vehicle, and reads out map data pertaining to an area at the current vehicle position from a data storage medium, for example, a CD-ROM (compact disc read-only memory), a DVD (digital versatile disc), or a hard disc. Typically, the navigation system displays a map image on a monitor screen while superimposing thereon a mark representing the current location of the user.
FIGS. 1A-1H show an example of overall procedure and screen display involved in the navigation system for route guidance to a destination. FIG. 1A shows an example of locator map screen of the navigation system when the destination is not specified. Typically, the navigation system displays a street on which the vehicle (current vehicle position VP) is running on a map image and a name of the street. Other information such as a north pointer NP, a map scale and a current time may also be illustrated on the display screen.
When a user selects to set a destination, the navigation system displays a “Find Destination by” screen as shown in FIG. 1B for specifying an input method for selecting the destination. When selecting, the “Point of Interest” method in FIG. 1B, the navigation system displays selection methods of point of interest (POI) either by “Place Name” or “Place Type” in FIG. 1C. If the “Place Type” is selected, the navigation system lists categories of POIs as shown in FIG. 1D.
FIG. 1E shows a screen when the user has selected a “Restaurant” category in FIG. 1D, which includes a list of names of POI type “Restaurant” typically sorted by distance from the current position. The user selects a desired destination, as shown in FIG. 1F and presses an “OK to Proceed” button for the navigation system to calculate an appropriate route to the destination. FIG. 1G shows an example of screen when the navigation system calculates and determines the route to the destination. After determining the route, the navigation system starts the route guidance to the destination as shown in FIG. 1H.
In the operation of the navigation system noted above, typically, the navigation system is able to calculate a route from a starting point to a destination and guide the user to the destination. In addition to such navigation function, the recent navigation system has other functionality, such as a communication capability, an audio player capability, an internet browser capability, etc. For example, with user of the wireless communication capability, the navigation system can receive and display the traffic condition with respect to the route to the destination.
In other words, the recent navigation system is able to provide not only the navigation function but also able to serve as a communication device, a man-machine interface, etc. Therefore, it is desirable to extend usability and functionality of the navigation system by making use of the ability of the navigation system. It is desirable to increase application of the navigation systems by exchanging information among a plurality of users through the wireless communicate function of the navigation system.